Conventionally, video magnetic disc recording is achieved by modulating the frequency of zero crossovers in a square wave current fed to the recording head. Erasure is achieved by a direct current supplied to the head so as to drive the magnetic medium into saturation. When erasure is followed by recording with a square wave having virtually no even harmonics, it is found that even harmonics are present in the replayed signal. The result of this is that the second harmonic is frequency-modulated with twice the deviation of the fundamental component. If the spectrum width of the baseband signal is not small compared to the frequency of the recording squarewave, interference beat patterns can be present in the demodulated video output. Furthermore, because the replayed signal is conventionally fed via a frequency doubler circuit and low-pass filter to the output, the carrier frequency can be present at the output. This conventional magnetic recording process introduces even order distortion in the replayed signals.